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Monday, April 19, 2010

Heart health differs depending on ethnicity: study - CTV News

Your chances of having the risk factors for heart disease can greatly depend on your ethnic heritage, new Canadian research suggests.

The study, conducted at Ontario's Institute for Clinical Evaluative Sciences (ICES), found that different ethnic groups can develop vastly different heart disease risk factors.

That might mean that "one-size-fits-all" strategies for preventing heart disease and stroke might be ignoring the unique needs of certain ethnic groups, the authors suggest in the article, published in the Canadian Medical Association Journal.

Among the ethnic differences the study found:

Obesity was five times more prevalent in Caucasian and black Ontario residents than people of Chinese heritage.

South Asians and blacks in Ontario have twice the risk of developing Type 2 diabetes than Caucasian and Chinese residents.

Cardiovascular disease (heart disease or stroke) was almost twice as prevalent in South Asians as in Chinese.

Blacks have a 44 per cent higher incidence of high blood pressure, and South Asians have a 24 per cent higher incidence, as compared to Caucasian Ontario residents.

Caucasians are almost three times more likely to smoke than Chinese and South Asian groups. Interestingly, rates of smoking in Chinese (8.7 per cent) and South Asian (8.6 per cent) residents of Ontario are significantly lower than in China (28.9 per cent) and India (15.6 per cent).

The study, which looked at more than 165,000 Ontario residents between 1996 and 2007, found that overall, Chinese respondents had the most favourable cardiovascular risk factor profile.

They noted that only 4.3 per cent of the Chinese population reported two or more major cardiovascular risk factors, which include: current smoking, obesity, diabetes, and high blood pressure.

That was followed by South Asians, among whom 7.9 per cent had two or more risk factors. A little over 10 per cent of Caucasian residents had two or more risk factors, while 11.1 per cent of black respondents had two risk factors.

The researchers noted an interesting "Black paradox": Though black residents had a higher prevalence of most cardiovascular risk factors, they had a lower prevalence of heart disease, at just 3.4 per cent.

South Asians had the highest prevalence of heart disease at 5.2 per cent.

Smoking was more common in men than women, but the difference between men and women was much smaller in the Caucasian and Black groups than in the Chinese and South Asian groups.

Between two-thirds and three-quarters of study participants didn't exercise at least 15 minutes a day. The problem was worst among South Asian men (70 per cent) and women (75 per cent), Chinese men (71 per cent) and women (75 per cent) and Black women (71 per cent).

The study, funded by the Heart and Stroke Foundation of Ontario, is considered the most comprehensive to date to determine health differences among ethnic groups in Canada.

"Although Canada is one of the most ethnically diverse countries in the world, relatively little is known about how Canada's four major ethnic groups differ in their cardiovascular risk profiles," said Maria Chiu, the principal investigator of the study and an ICES Doctoral Fellow.

Dr. Chi-Ming Chow, a cardiologist and Heart & Stroke Foundation of Ontario spokesperson, says it's important that these ethnic differences be highlighted.

"People can actually develop these important risk factors -- these silent killers that may not have any symptoms – at an early age," he told CTV News.

"So many people think ‘I'm fine. I don't need to see a doctor. I'm feeling well.' But they may be hiding all these important risk factors like diabetes, high blood pressure, high cholesterol."

The authors note that there are nearly 2 million people of South Asian, Chinese or Black descent living in Ontario and more than 9 million people of European descent.

And while people of South Asian, Chinese and black ethnic background represent approximately 60 per cent of the world's population, the body of knowledge of cardiovascular risk has been derived mainly from studies conducted in Caucasian populations.

Dr. Marco Di Buono, Director of Research at the Heart and Stroke Foundation of Ontario noted that many of Canada's ethno-cultural communities have unique linguistic and cultural challenges to overcome with respect to improving their heart health.

"We need to address these challenges to ensure the long-term heart health of all Canadians, including new immigrants coming to this country," he said in a statement.